Angular contact ball bearings are generally selected for applications wherein loading occurs in both the axial and radial directions. These bearings may be used in relatively high speed, precision applications including, for example, dental applications, turbo chargers, electric motors, automotive applications, pumps and compressors. However, problems remain due to bearing retainer wear, which is generally understood to be the one of the leading causes of a high speed bearing failure.
For example, retainers used in high speed applications, such as high speed dental handpieces, may be piloted (guided) by the inner or outer bearing ring land surfaces, requiring physical contact between the retainer, formed of a relatively softer material, such as a polymer resin, and the bearing ring land surface, formed of a relatively harder material. Guiding is specifically necessary in the bearings working at extremely high speeds, for example in dental handpieces rotating with the speeds up to 500,000 RPM, to minimize and limit uncontrollable otherwise retainer vibrations. Guiding requires a physical contact between the retainer and ring causing the retainer to wear. Therefore, a need still remains in the bearing industry to avoid or minimize retainer wear that could ultimately lead to premature failure.